The long, yellow, oval pill with 200 on one side is Rezulin 200 milligrams. Known by the generic name Troglitazone, it is available only by prescription, notes Drugs.com.
Rezulin is used in the treatment of type 2 diabetes and belongs to the drug class thiazolidinediones. Troglitazone is an antihyperglycemic agent that helps the body better respond to insulin. It reduces the amount of sugar produced by the liver and can help control blood sugar levels. As of 2015, troglitazone is not available in the United States, as it has been known to cause severe liver damage resulting in death or the need for a liver transplant, explains Drugs.com.